1. Field of the invention
This invention relates to an apparatus for adjusting the inclination of an automobile headlamp, driven by a motor.
2. Description of the prior art
A conventional apparatus of this type is designed to obtain an adequate direction of an optical axis of a lamp (the direction of an optical beam emitted from a lamp) by compensating the variation in the optical axis of the lamp due to a heavy load carried in a vehicle and particularly in a truck for loading heavy luggages. When the optical axis of the lamp thus varies, a driver cannot attain a suitable visual field in driving the vehicle, or the vehicle emits glazed lights from the headlamps toward an opposed vehicle on a road, which might cause a very dangerous accident. The optical axis regulator of this sort is devised to solve the above-described problems.
In a conventional apparatus for adjusting the inclination of an automobile headlamp known per se such as a device disclosed in U.S. Pat. No. 4,241,260 specification, a drive motor is connected to a power source through an operation switch having a contact corresponding to the predetermined angular position of headlamps and a changeover switch for reversely rotating the rotating direction of the motor. The motor is driven by opening or closing of such switch means, and driven until the headlamps are directed to predetermined angular position. In this device, the more the number of the angular positions of the headlamp increases, the greater the number of contacts of the operation switch and the changeover switch increase, thereby resulting in the complexity in the structure of the switches.
In another conventional device disclosed in U.S. Pat. No. 4,197,491 specification, the headlamp can be moved from a certain angular position to other angular position by switching an operation switch in the same manner as the device disclosed in U.S. Pat. No. 4,241,260 specification, but it is necessary to independently provide switch means for reversely rotating the rotating direction of the motor. Thus, since a driver should operate both the operation switch and the changeover switch for reversely rotating the motor, a drawback that the operations of the switches become complicated arises.